摘要目的:探讨老年与中青年食管鳞癌（esophageal squamous cell carcinoma， ESCC）患者食管组织的菌群特征及差异，以助于研究老年ESCC患者潜在的生物标志物。方法:采用回顾性研究，选取2018年7月至2019年7月在湖北省十堰市太和医院确诊的72例ESCC患者，其中老年组49例（≥60岁，男性40例，女性9例），中青年组23例（<60岁，男性21例，女性2例），以同期消化内镜中心20名胃镜检查无异常的健康体检者作为对照组（年龄范围35~78岁，中位年龄57岁，男性16名，女性4名）。收集ESCC患者病变食管组织和健康对照组中段食管组织、提取基因组DNA，对细菌16SrRNA基因序列V4高变区扩增，采用Illumina HiSeq测序技术，对比分析老年和中青年ESCC患者菌群特点。采用QIIME和Rstudio软件分析序列数据，统计学方法采用非参数Kruskal-Wallis检验或Wilcoxon秩和检验。结果:两组患者菌群Shannon指数［5.17（4.53，5.95）比4.79（3.74，5.97）］、Simpson指数［0.94（0.91，0.96）比0.92（0.83，0.96）］和Chao1 ［343.55（259.76，570.59）比329.16（268.88，648.00）］指数相似，差异无统计学意义（ Z=-0.791、-1.057、-0.380，均 P>0.05）；Beta多样性老年组与中青年组亦无明显差异（PC1=19.14%、PC2=6.95%， PPC1=0.67、 PPC2=0.42）。在门水平，中青年组丰度前五的菌门依次为厚壁菌门（ Firmicutes）、拟杆菌门（ Bacteroidetes）、变形菌门（ Proteobacteria）、放线菌门（ Actinobacteria）和梭杆菌门（ Fusobacteria），老年组患者丰度最高的五个门分别是厚壁菌门（ Firmicutes）、拟杆菌门（ Bacteroidetes）、变形菌门（ Proteobacteria）、梭杆菌门（ Fusobacteria）和放线菌门（ Actinobacteria）；两组差异显著的是梭杆菌门（ Fusobacteria）（ Q=0.596， P<0.05）。在属水平，中青年组丰度前五的菌属依次为：普雷沃菌属（ Prevotella）、拟杆菌属（ Bacteroides）、链球菌属（ Streptococcus）、月形单胞菌属（ Selenomonas）和韦荣球菌属（ Veillonella）；而老年组丰度前五的分别是普雷沃菌属（ Prevotella）、拟杆菌属（ Bacteroides）、链球菌属（ Streptococcus）、月形单胞菌属（ Selenomonas）和嗜血杆菌属（ Haemophilus），两组有显著差异的为梭杆菌属（ Fusobacterium）（ Q=0.938， P<0.05）。基于未观测状态重建的群落系统发育研究（PICRUSt）功能预测，老年组患者氨酰tRNA生物合成（ Aminoacyl.tRNA.biosynthesis）、核苷酸切除修复（ Nucleotide.excision.repair）、核糖核酸聚合酶（ RNA.polymerase）、核糖体（ Ribosome）、克拉维酸生物合成（ Clavulanic.acid.biosynthesis）、光合作用（ Photosynthesis）和光合作用蛋白（ Photosynthesis.proteins）丰度较中青年组降低（均 Q=0.734， P<0.05）。 结论:老年ESCC患者食管菌群与中青年患者的Alpha多样性和Beta多样性无明显差异，但老年患者梭菌属菌群丰度增高。

abstractsObjective:To explore the flora characteristics and differences of esophageal tissues between elderly esophageal squamous cell carcinoma (ESCC) patients and young and middle-aged ESCC patients, so as to assist in studying the potential biomarkers of elderly ESCC patients.Methods:In this study, a retrospective study was adopted. 72 ESCC patients diagnosed in Taihe Hospital, Shiyan City, Hubei Province from July 2018 to July 2019 were selected, including 49 patients in the elderly group (≥ 60 years old, 40 males and 9 females), 23 patients in the young and middle-aged group (<60 years old, 21 males and 2 females). In the same period, 20 healthy persons without abnormal gastroscopy in endoscopy center were selected as the control group (aged 35-78 years old, median age 57 years old, 16 males and 4 females). The genomic DNA was extracted from the affected esophageal tissues of patients with ESCC and the middle esophageal samples of the control group. The V4 hypervariable region of bacterial 16SrRNA gene sequence was amplified. Illumina HiSeq sequencing technology was adopted. The flora characteristics of elderly, young and middle-aged ESCC patients was compared and analyzed. QIIME and Rstudio software were used to analyze the sequence data, and nonparametric Kruskal-Wallis test or Wilcoxon rank sum test were used for statistical methods.Results:Shannon index [5.17 (4.53, 5.95) vs. 4.79 (3.74, 5.97)], Simpson index [0.94 (0.91, 0.96) vs. 0.92 (0.83, 0.96)] and Chao1 index [343.55 (259.76, 570.59) vs. 329.16 (268.88, 648.00)] were similar in flora of two groups, and there was no significant difference ( Z=-0.791, -1.057, -0.380, all P>0.05). There was no significant difference in β-diversity between the elderly group and the young and middle-aged group (PC1=19.14%, PC2=6.95%, PPC1=0.67, PPC2=0.42). At the phyla level, the top 5 phyla in abundance were as follows: Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria and Fusobacteria in the young and middle-aged group, while the top 5 phyla in abundance were as follows: Firmicutes, Bacteroidetes, Proteobacteria, Fusobacteria and Actinobacteria in the elderly group; the significant difference between the two groups was Fusobacteria ( Q=0.596, P<0.05). At the genus level, the top 5 genera in the young and middle-aged group in abundance were as follows: Prevotella, Bacteroides, Streptococcus, Selenomonas and Veillonella. In the elderly group, Prevotella, Bacteroides, Streptococcus, Selenomonas and Haemophilus were the top 5 in abundance, and there were significant difference in Fusobacterium between the two groups ( Q=0.938, P<0.05). PICRUSt function prediction showed that the abundance of Aminoacyl.tRNA.biosynthesis, Nucleotide.excision.repair, RNA.polymerase, Ribosome, Clavulanic.acid.biosynthesis, Photosynthesis and Photosynthesis. proteins in the elderly group were lower than those in the young and middle-aged group (all Q=0.734, P<0.05). Conclusion:There is no significant difference in α-diversity and β-diversity between elderly ESCC patients and young and middle-aged patients, but the abundance of Fusobacterium flora increased.